The effect of enzymatic hydrolysis and polysaccharide addition on the interfacial adsorption of beta-lactoglobulin (beta-LG) was investigated in this work. The enzymatic treatment was performed in the hydrolysis degree (HD) range of 0.0-5.0% using bovine alpha-chymotrypsin II immobilized on agarose beads. Anionic non-surface active polysaccharides (PS), sodium alginate (SA) and lambda-carrageenan (lambda-C) were studied in the concentration range of 0.0-0.5 wt.%. The adsorption process at the air-water interface was evaluated by means of tensiometry and surface dilatational rheology. Biopolymer interactions in solution were analyzed by extrinsic fluorescence spectroscopy. The enzymatic hydrolysis improved beta-LG interfacial properties. On the other hand, at low HD (1.0%), PS addition enhanced surface and elastic properties of beta-LG hydrolysate films probably due to a higher repulsion between biopolymers in solution. However, at high HD (3.0-5.0%), SA addition caused a deterioration of surface and elastic properties of beta-LG hydrolysate films probably due to the segregation and hydrolysate aggregation in solution, whereas lambda-C addition could promote the formation of soluble complexes leading to a better control of elastic properties of beta-LG hydrolysate films. (C) 2011 Elsevier Ltd. All rights reserved.